Renal Denervation Effects on Myocardial Fibrosis and Ventricular Arrhythmias in Rats with Ischemic Cardiomyopathy

Cellular Physiology and Biochemistry

Bin Zhang¹ 

关键词: Renal Denervation;    Myocardial Infarction;    Ventricular Arrhythmia;    Fibrosis;    Connexin;   

DOI  :  10.1159/000489653

学科分类：分子生物学，细胞生物学和基因

来源: S Karger AG

【 摘 要 】

Background/Aims To investigate the impact of renal denervation (RDN) on myocardial fibrosis and ventricular arrhythmias (VAs) in rats with ischemic cardiomyopathy. Methods An ischemic cardiomyopathy model was reproduced with myocardial infarction (MI) in adult Sprague–Dawley male rats. The RDN/Sham-RDN procedure was performed at 2 weeks after MI. Sham-MI and sham-RDN rats served as the control group. At 4 weeks after RDN, programmed electrical stimulation (PES) was used to induce VAs, including ventricular tachycardia and ventricular fibrillation, in all 3 groups (MI+RDN, MI, and control groups). At the end of PES, heart and kidney samples were harvested. Immunofluorescence labeling was used to investigate the distribution of connexin 43 (Cx43) in the infarcted border zone. Masson’s trichrome stain was adopted to determine the degree of cardiac fibrosis. Western blotting was performed to identify the expression of transforming growth factor beta 1 (TGF-β1), α-smooth muscle actin (α-SMA), and Cx43. An enzyme-linked immunosorbent assay (ELISA) was used to detect the serum levels of B-type natriuretic peptide (BNP) and the amino-terminal pro-peptides of type I and III collagen (PINP and PIIINP, respectively) and the expression level of renal norepinephrine. Results Compared with the MI group, RDN significantly decreased the inducibility of VAs (MI+RDN 3/8 rats vs. MI 8/9 rats, P < 0.05; control 1/8 rats) with PES, reduced myocardial fibrosis estimated by collagen volume fraction (MI+RDN 31.10 ± 3.97% vs. MI 54.80 ± 16.39%, P < 0.001; control 4.41 ± 0.92% ), suppressed TGF-β1 (P < 0.01) and α-SMA (P < 0.001) levels, and attenuated both PINP (MI+RDN 41.44 ± 10.10 ng/mL vs. MI 95.49 ± 24.83 ng/mL, P < 0.001; control 11.90 ± 4.96 ng/mL) and PIIINP (MI+RDN 82.12 ± 30.79 ng/mL vs. MI 124.60 ± 26.64 ng/mL, P < 0.05; control 64.69 ± 23.84 ng/mL) levels. Moreover, RDN reversed the abnormal myocardial distribution of Cx43 and its reduction by MI damage (P < 0.01). Conclusions RDN reduced myocardial fibrosis and suppressed VAs in a rat model of ischemic cardiomyopathy.

【 授权许可】

CC BY-NC-ND